How to select the right Ex-certified equipment?

When operating in a potentially explosive atmosphere, there are several crucial aspects to look out for. This includes understanding the potential hazards and choosing the correct tools for the identified hazardous area.

When operating in a potentially explosive atmosphere, there are several crucial aspects to look out for. This includes understanding the potential hazards and choosing the correct tools for the identified hazardous area.

The Cygnus 1 Ex Ultrasonic Thickness Gauge is certified intrinsically-safe to Zone 0 – the most hazardous area, negating the need for Hot Work Permits. But what does it really mean? Let’s decipher these statements and explain the rules and regulations surrounding the use of equipment in hazardous areas.

Intrinsically-Safe vs Explosion-Proof

‘Intrinsically Safe’ is one of the protection concepts used to define Ex equipment designed for safe operation in hazardous locations. The Cygnus 1 Ex gauge uses intrinsic safety protection to limit the energy present in its system, meaning it is insufficient to ignite a hazardous atmosphere under any conditions. This includes low power levels and low stored energy. Intrinsically-safe equipment can be Ex-certified to Zone 0, 1 or 2.

Another concept often used is ‘Explosion-proof’ (or ‘flame-proof’). This type of equipment is sealed and rugged, such that it will not ignite a hazardous atmosphere. However, it is possible for a spark or explosion to be generated within the equipment itself. For this reason, ‘Explosion-proof’ equipment can only be Ex certified to Zone 1 or 2.

This means that only Intrinsically-Safe equipment can be used in Zone 0.

What you need to know about Equipment Protection Levels (EPLs)

All certified Ex equipment (portable or fixed) designed for operation in hazardous areas, will have an Ex Certificate of Conformity (C-of-C) which states its Equipment Protection Level (EPL), represented by a ‘G’ code. The table below shows the correlation between Zones, EPLs and different protection concepts. Cygnus uses the Intrinsically Safe protection type for its Ex products.

Cygnus 1 Ex does not require a Hot Work Permit

Hot Work Permits are used to mitigate the risks of hot work tools or processes capable of creating a spark or generating enough heat to ignite a gas. Thanks to its Intrinsic Safety design, the Cygnus 1 Ex gauge cannot generate sufficient energy to cause an explosion and, therefore, can be used safely within hazardous areas at any time without the need for a Hot Work Permit.

This saves a lot of hassle as obtaining a Hot Work Permit is normally costly and time-consuming. A formal application with a risk assessment is required, along with methods to remove or reduce the risks.

Typically for a permit in a hazardous area:

• The permit must be authorised by a senior person

• A competent person is required to check gas levels

• Oxygen levels and flammable substances must be frequently monitored

• Persons should be competent in emergency response and first aid

• Specialist rescue equipment on standby is required

• Pipes and tanks may need to be purged with nitrogen

• Plant operations should be shutdown.

Hot Work Permits can be very inconvenient and must be planned. It’d be far easier to use Ex equipment.

The Cygnus 1 Ex is the world’s only Zone-0 UTM gauge certified to ATEX, IECEx, UKEX for use in all Hazardous Zone 0, 1 and 2. Featuring 3 measuring modes and the Deep Coat function, this versatile UTM gauge can measure the wall thickness of various materials through thick coatings or extreme corrosion. The A-Scan and B-Scan functions provide additional measurement verification and cross-sectional display whilst the data logging capability records measurements with A-Scans for hassle-free reporting and analysis. Furthermore, the Manual Measurement Mode allows manual gates and gain to be configured to suit your application. When coupled with Cygnus’ High-Temperature Ex probe, the gauge transforms into a high-temperature thickness gauging kit for efficient corrosion inspection on hot assets in-service, without needing for plant shutdown or Hot Work Permits.

Despite various advanced functionalities, the Cygnus 1 Ex is surprisingly easy to operate – thanks to 4 function keys for easy controls and dynamic views, 4 measurement screens, and an intuitive menu. Like all Cygnus products, the Cygnus 1 Ex thickness gauge is manufactured in the UK and has a 3-year warranty.